1. Field of the Invention
The invention relates to an MIS-semiconductor component with a substrate in which a first zone of a first conduction or conductivity type is embedded; a second zone of a second conduction type which is embedded in the first zone; at least one insulating layer lying on the substrate surface; and a contact making connection with the first and the second zone through a hole formed in the insulating layer.
2. Description of the Prior Art
Such a semiconductor component has already been described in the form of an MOS field-effect transistor with a vertical structure. In that structure, the first zone forming the channel zone and the second zone forming the source lie at the surface of the substrate, while the drain zone covers the substrate on the underside over a large surface. To obtain good electrical properties, such as a low set-in voltage, the channel must be kept short. The second zone forming the source zone must also be made very thin. In addition, it cannot be doped very heavily because otherwise diffusion under the insulating layer serving as the masking would occur. Thus, the channel length can no longer be made reproducible.
Contacting such a thin, relatively weakly doped layer with the aluminum or an aluminum-silicon alloy normally used as the contact now presents difficulties, particularly if the source zone is n-conducting, since aluminum in silicon has a p-doping effect.